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This paper describes the design and operation of a sampling valve suitable for time resolved sampling of gases from the cylinder of an operating engine. A continuous flow of cylinder gas passes through the valve orifice. The valve diverts a small portion of this flow to a sample collection volume upon demand. The flow diversion is accomplished by action of an internal rotating sampling tube mechanism. The sampling period is 1 msec or less. The sampling system has been operated successfully in a fired Diesel engine for insertion depths of up to one-quarter inch.

The theory, development, and calibration of an electro-optical pyrometer, capable of determining instantaneous true temperatures of luminous flames, are described. A description is also given of auxiliary apparatus used with the electro-optical pyrometer to obtain simultaneous values of pressure, temperature, and crank position in an internal-combustion engine. Typical data obtained with this instrumentation as applied to a Diesel engine are included.

Flame-temperature data obtained with the electro-optical pyrometer developed at the University of Wisconsin, and performance curves showing the influence of operating variables are presented. Unique contour graphs show combustion characteristics in a form that facilitates visualization of the existing relationships. Observed combustion trends are pointed out and discussed.

In a spark-ignited internal combustion engine there are two zones of interest ( a) the burnt mixture and ( b) the unburnt mixture. Of interest to the authors and to many of their colleagues are the pre-reactions which occur in the unburnt zone. To follow the extent of these pre-reactions both the pressure and the temperature of the unburnt mixture are required. Pressure transducers can be obtained from many commercial establishments, but a temperature pyrometer that can follow the temperature of the unburnt mixture is not commercially available. The current technique uses the absorption, emission characteristic of the water vapour in the cylinder. The use of water vapour as the sensing element is desirable since water vapour is normally in the air which the internal combustion (i.c.) engine breathes. Radiation of a known intensity (known black-body temperature) is passed through the engine, through a band pass filter (H2O water vapour band at 2.6 μ) to an infra-red detector. The output from the detector, after amplification, is fed to a cathode-ray oscilloscope. By suitable means, it is possible to compare the undisturbed radiation from the black body with the black-body radiation after it has experienced absorption emission events during the compression process. The reversal point can be visually observed on the oscillogram. At this reversal point the temperature of the gas and the black body are equal and the crank angle at which this occurs can be determined. Other temperatures and crank angles at which reversal occurs can be observed to obtain the unburnt mixture temperature versus crank angle curve. The authors' experiences with different infra-red detectors and other temperature-measuring techniques, as well as comparison between the velocity of sound method and the infra-red technique, are discussed. Data obtained with the instrument are presented.

A spray-burning model (based on single-droplet theory) for heat release in a diesel engine is presented. Comparison of computations using this model and experimental data from an operating diesel engine indicate that heat release rates are not adequately represented by single-droplet burning rates. A new concept is proposed, i.e. a burning coefficient for a fuel spray. Comparisons between computations and experimental data indicate that the numerical value of this coefficient is nearly independent of engine speed and combustion-chamber pressure. However, the instantaneous value of the spray burning coefficient is approximately proportional to the instantaneous mass-averaged cylinder gas temperature to the one-third power.

A kinetic reaction model for the reaction of ethane in spark-ignition engine-exhaust gases was constructed, based on mechanisms and rate constants currently available in the literature. The model consists of 33 elementary chemical reactions involving 20 chemical species and was tested by comparing calculated and experimentally measured species concentrations resulting from a step increase in the ethane concentration of isothermal, steady-flow, hydrocarbon-free exhaust gases. For the range of conditions, 950°–1000°K, 1.2%–3.6% oxygen, and 700–1400 ppm ethane, good agreement was obtained between experimental and calculated concentrations of the major species, ethane, ethylene, carbon monoxide, and formaldehyde. The agreement between experimental and calculated results indicate that reacting hydrocarbons may have an adverse effect on the oxidation of carbon monoxide.

The theory, development, and calibration of an electro-optical sodium-line reversal pyrometer are given. This pyrometer instantaneously and continuously determines and indicates the black-body temperature of a non-luminous flame made luminous at the sodium wave length by the addition of sodium. Typical data obtained on a spark-ignition engine are presented and compared with data obtained by previous investigators. A correlation of these data with combustion-chamber design indicates the possible existence of a high temperature in the flame front.

Gas concentrations under different engine operating conditions and different locations relative to the fuel spray are presented. The gas that is sampled is ''snatched'' from a continuous flow sampling probe. The time of snatching is controlled. The concentrations of CO, CO/sub 2/, NOx, and O/sub 2/ are plotted against crank position. The sampled gases were analyzed for concentration in the as taken state and after the sampled gas had passed through a heated catalytic oxidation converter. Analyses have been performed and plots are presented of the findings. The analytic procedure developed for the data analysis is presented in detail.

A single cylinder engine was used to simulate the delayed mixing stratified charge combustion process. A rich charge was drawn into the engine through the carburetor. Combustion was inititate with a spark; later air was injected to complete the combustion process. The results showed that emissions could be controlled by the delayed mixing combustion process. The engine specific power was also at reasonable levels. However, the engine efficiency was low. /SASI/

The growth in population (Fig. 1) plus the growth in energy consumption per person(1) have combined together to give dramatic increases in both air and water pollution problems. The automotive vehicle has been a significant contributor to air pollution on a total mass basis (Fig. 2), although its contribution is considerably smaller if the toxicity of emissions as well as the quantity of emissions is considered (Fig. 3).(2) Thus, the purpose of this paper is to first of all indicate why certain exhaust constituents from automotive vehicles are considered as pollutants, to describe how these pollutants are formed in automotive vehicle operation, and finally, to describe control techniques being used and considered. As indicated in the title, the paper is intended to educate by organizing and systematizing existing information rather than presenting primarily new information.